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BC Conservation Data Centre: Species Summary


Gavia adamsii
Yellow-billed Loon

 
Scientific Name: Gavia adamsii (Gray, 1859)
English Name: Yellow-billed Loon
 
Classification / Taxonomy
Scientific Name - Concept Reference: American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, D.C. [as modified by subsequent supplements and corrections published in The Auk]. Also available online: http://www.aou.org/.
Classification Level: Species
Species Group: Vertebrate Animal
Species Code: B-YBLO
Kingdom Phylum Class Order Family
Animalia Craniata Aves Gaviiformes Gaviidae
   
Conservation Status / Legal Designation
Global Status: G4 (Apr 2016)
Provincial Status: S2S3N (Mar 2015)
BC List: Blue
Provincial FRPA list:   
Provincial Wildlife Act:
COSEWIC Status: Not at Risk (May 1997)
SARA Schedule:
General Status Canada: 4 - Secure (2005)
Migratory Bird Convention Act: Y
   
Ecology & Life History
General Description: Distinguished from other four loon species by the color of its bill, which is yellow in breeding plumage and pale yellow to ivory in wintering plumage. Breeding plumage has black upper parts with striking white spots, black head and neck with purple and green gloss, and white chest and abdomen; non-breeding plumage is gray-brown. In all plumages, top part of culmen (ridge of upper mandible) is yellow and distinguishable from other species of loon (North 1994, Earnst 2004). Like other loons, this species has a highly modified leg and pelvis structure well-adapted for swimming and diving but allowing almost no ability to walk; therefore, loons place nests at the water's edge and must take flight from water (Earnst 2004).
Global Reproduction Comments: Pair formation occurs upon arrival on breeding territory; nests are constructed early to mid-June (North 1994). Nests comprised of peat, pendant grass (Arctophila fulva), sedges (Carex spp.) and sometimes lined with other vegetation (North and Ryan 1988 in Earnst 2004); nests from previous years frequently reused. Eggs are laid in June-July (some July nests represent renestings after loss of eggs); first nests generally are in mid-June in arctic Alaska, but peak nesting may be delayed by late ice melt on lakes. Clutch size: 2. Incubation, by both sexes, lasts 27-28 days. Chicks are dry and active within hours of hatching; brooding by both parents occurs in nest for ~3 days, then little on-shore brooding after ~9 days (North 1994). In some areas, chicks 9-16 days old observed riding on parents back (Sjolander and Agren 1976 in North 1994). Adults forage to feed young for up to 45 days (Earnst 2004). Reproductive maturity probably reached at or after 4 years.
Global Ecology Comments: Breeding density is low compared to other loons (estimated at one individual per 10 sq km in Alaska) (Johnsgard 1987); defends large territory, usually 17 ha to > 100 ha, used for nesting and brood rearing (Earnst 2004).
Migration Characteristics:
(Global / Provincial)		 
    Nonmigrant:
    Local Migrant:
    Distant Migrant:
    Within Borders Migrant: 		N /
N /
Y /
na /
Global Migration Comments: Migrates between breeding range in arctic tundra regions and non-breeding areas farther south and east. Arrival dates along Alaska coast from St. Lawrence Island to Colville River Delta usually May 15-June 1; at Colville River Delta, usually May 31-June 3; east of Colville River and in Canada, usually June 1-15 (North 1994). Departure in fall generally occurs from late August to mid-September in Alaska, to October in Canada; closely associated with fledging of offspring (Earnst 2004). Migrates singly, in pairs or in loose flocks; occasionally stages in larger groups in the fall (North 1994).
Habitats:
(Type / Subtype / Dependence) 		Lakes / Lake / Facultative - occasional use
Lakes / Pond/Open Water / Facultative - occasional use
Ocean / Intertidal Marine / Facultative - frequent use
Ocean / Kelp Bed / Facultative - occasional use
Ocean / Pelagic / Facultative - occasional use
Ocean / Sheltered Waters - Marine / Facultative - frequent use
Ocean / Subtidal Marine / Facultative - frequent use
Other Unique Habitats / Estuary / Facultative - occasional use
Global Habitat Comments: Breeding: Nests in low-lying treeless tundra regions, usually coastal, at around 62-74 degrees latitude on larger (in Alaska, 8-229 ha), clear, low-rimmed lakes. Breeding sites may also be on inland lakes or large river deltas with untapped lakes (North 1994, Fair 2002). Requires nesting and brood-rearing lakes that are large enough to allow easy take-off from open water; form an ice-free moat around shore in early spring; have clear water supporting a substantial overwintering population of small fishes; have segments of gently sloping shoreline in which nesting and brooding occurs; and have sheltered, vegetated areas, where young chicks rest and take refuge during disturbances (Earnst 2004). Lake size, depth, connectivity to streams, shoreline complexity and proportion of shoreline in moist to aquatic cover types were each significant predictors in a survey of 757 lakes in northern Alaska (Earnst 2004). Nests placed at the water's edge, typically in a low, gently sloping area. Deep open water with islands is a preferred habitat for nesting relative to its availability. Most nests are placed on the leeward lake or island shore (Earnst 2004).

Non-breeding: Little studied, generally near shore, in protected waters, from 50-61 degrees N (North 1994). Spend roughly eight months exclusively in marine environments. During migration, prefer open-water leads for resting and refueling (Earnst 2004).
Food Habits: Invertivore: Adult, Immature
Piscivore: Adult, Immature
Global Food Habits Comments: Forages in deep open water by repeated, lengthy dives. May forage at lake adjacent to nesting lake. An opportunistic forager, takes prey in relation to availability and ease of capture, and consumes underwater. Chicks are fed small, minnow-sized fish. Important prey species include ninespine stickleback (Pungitius pungitius), least cisco (Coregonus sardinella), Alaska blackfish (Dallia pectoralis), fourhorn sculpin (Myoxocephalus quadricornis), isopods and amphipods (Earnst 2004).
Global Phenology: Diurnal: Adult, Immature
Provincial Phenology:
(1st half of month/
2nd half of month)
Colonial Breeder: N
Length(cm)/width(cm)/Weight(g): 86/ / 5438
Elevation (m) (min / max): Global: 
Provincial: 
   
 
Distribution
Endemic: N
Global Range Comment: Breeding range extends patchily throughout the subarctic and arctic tundra of northern Alaska, Canada, and Eurasia. In Alaska, nesting occurs from the Canning River westward to Point Lay and also includes St. Lawrence Island and coastal areas of the Seward Peninsula. In Canada, breeding extends from just east of the MacKenzie River Delta to Hudson Bay, including northern islands. Breeding is most common on Banks and Victoria Islands and in the lake district from Great Slave Lake northeast to northern Hudson Bay, and nesting occurs sparsely elsewhere. In Russia, nesting occurs in narrow strip of coastal tundra from the Chukchi Peninsula in the east to the Taymyr Peninsula and the areas of the Novaya Zemlya River and Pechora River in the west. Small numbers have been reported breeding in Finland and Norway (Earnst 2004).

Migration occurs regularly along the coastlines of northern Canada and northern and northwestern Alaska and rarely along the western Alaska coast (Earnst 2004).

In winter, the species is regularly but sparsely distributed in nearshore marine waters from Kodiak Island though Prince William Sound, and throughout southeast Alaska and British Columbia. Irregular wintering occurs southwest of Kodiak Island along the Aleutian Islands and along the coast from Washington to Baja California. Several reliable inland sightings exist for migrating and wintering loons in western and central North America. Immatures and possibly some nonbreeding adults remain on wintering grounds throughout the year. Eurasian population winters primarily around Scandinavia and along the Pacific Coast of Siberia, uncommonly in northern Japan, and rarely in China, Great Britain, and continental Europe (Earnst 2004).
 
Authors / Contributors
Global Information Author: Gotthardt, T.A., A. Jansen, and G. Hammerson
Last Updated: Jan 17, 2005
Provincial Information Author:
Last Updated:
   
References and Related Literature
American Ornithologists' Union (AOU). 1983. Check-list of North American Birds, 6th edition. Allen Press, Inc., Lawrence, Kansas. 877 pp.
Campbell, R.W., N.K. Dawe, I.McT. Cowan, J.M. Cooper, G. Kaiser, and M.C.E. McNall. 1990. The Birds of British Columbia, Vol. 1. Nonpasserines: Introduction, Loons through Waterfowl. Royal B.C. Mus. in association with Environ. Can., Can. Wildl. Serv. 514pp.
Cogswell, H. L. 1977. Water birds of California. Univ. California Press, Berkeley. 399 pp.
Field, R., M. R. North, and J. Wells. 1993. Nesting activity of yellow-billed loons on the Colville River Delta, Alaska, after the EXXON VALDEZ oil spill. Wilson Bull. 105:325-332.
Harrison, C. 1978. A Field Guide to the Nests, Eggs and Nestlings of North American Birds. Collins, Cleveland, Ohio.
Johnsgard, P. A. 1987. Diving birds of North America. Univ. Nebraska Press, Lincoln. xii + 292 pp.
Johnson, S. R. and D. R. Herter. 1989. The Birds of the Beaufort Sea. BP Exploration (Alaska) Inc., Anchorage, Alaska. 372 pp.
North, M. R., and M. R. Ryan. 1988. Yellow-billed Loon, GAVIA ADAMSII, breeding chronology and reproductive success in arctic Alaska. Canadian Field-Naturalist 102:485-490.
Stallcup, R. 1994. Focus: loons. Point Reyes Bird Observatory, Fall 1994, pp. 6-7.
Terres, J. K. 1980. The Audubon Society encyclopedia of North American birds. Alfred A. Knopf, New York.
 

Please visit the website Conservation Status Ranks for definitions of the data fields used in this summary report.

Suggested Citation:

B.C. Conservation Data Centre. 2005. Species Summary: Gavia adamsii. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 27, 2026).